You've probably heard this one before, but it bears repeating. Targeting 100 major influencers can be exponentially more effective than than getting 5,000 less influential followers. The reason? When an influencer retweets what you say or comments on a link, you can reach hundreds of thousands of Twitter or Facebook users in an instant. But having 5,000 (or even 50,000) followers who are not really that interested in what you have to say is a dead end. If you make a mobile app, try to get the attention of a pundit who covers that space. If you do real estate consulting, see if an expert in your area will follow your tweets.
2. Put a face to a name.
I developed a habit of always looking up the details for new followers or those who retweet my posts. Social media is supposed to be social, so get to know those who are following you. This helps in several ways. Our brains are wired for visual cues. When you see that Joe Smith lives in Texas and likes Red Bull, you'll form a mental connection. When you develop a rapport with someone (say, you joke with them about Red Bull) that encourages more retweeting and a more social connection. (The same is true in real life, by the way.) A tighter bond with people goes both way--you'll also retweet what they say. One tool to help you see the real person behind a post is called Rapportive.
3. Always respond.
I used to avoid this one. When someone didn't like one of my tweets, I'd ignore it. But in reality, creating a dialogue helps further the social connection, even if it seems like a negative topic. One example: I've seen people post about how they hated one of my articles. Instead of ignoring the criticism, I'll try to interact with them and discuss what they didn't like. Maybe it helps me improve as a writer. But it also means everyone else is seeing that I care enough to respond--I'm not just an AI bot. (That said, it's still okay to ignore trolls who are only stirring up dissension, or automated responses from those bots.)
4. Schedule yourself.
I have not always followed this dictum, but it does work. Like any blog or news site, the more active you appear on Twitter or Facebook the better. Scheduling posts with a tool like HootSuite, where you can set a post to go live at a later date and time, means you are making sure you have an active presence. It's also a good idea to target "prime time" on the social graph, such as just after the workday starts or right before people leave for the day. And, don't forget to do this for multiple time zones.
5. Venture beyond Twitter and Facebook.
The two most popular social networking sites get all of the attention, but that also makes them easier to ignore for people who have been using those services for a while. Newer sites like Pinterest might be a better place to develop a following, depending on your subject matter, because they have a critical mass of people clicking around and checking them out. And while I've been critical of Google Plus, there is a loyal base of tech pundits there. Keep an eye out for emerging social hotspots.